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You are inspecting the lower main precision bearings on a diesel engine.You observe that about half the thin Babbitt linings are of a milky white colourThis condition is caused by （）
A . large dirt particles in the oil supply
B . insufficient lubricating oil and overheating
C . normal wear
D . water contamination of the lube oil
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When you compare the differences between half-duplex and full-duplex Ethernet,which of the following characteristics are exclusive to half-duplex?（）
A . Half-duplex Ethernet operates in a shared collision domain.
B . Half-duplex Ethernet operates in an exclusive broadcast domain.
C . Half-duplex Ethernet has efficient throughput.
D . Half-duplex Ethernet has lower effective throughput.
E . Half-duplex Ethernet operates in an exclusive collision domain.
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Why are the 1300 nm and 1550 nm regions of the fiber spectrum primarily used for optical communications？（）
A . They are both regions of lowest loss.
B . They are both regions of low reflections.
C . They are both regions of low index of refraction.
D . They are both regions of low chromatic dispersion.
E . They are both regions of low Polarization Mode Dispersion （PMD）.
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The examples of the half-squatting, half-kneeling archers in Pit No. 2 are used to illustrate _________ .
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Why are some of the works of Steinbeck considered controversial?
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Why are people on the Miguel Street scared of Big Foot?
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Why is the mother of the narrator almost cry from joy when seeing the sceneries?
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More than half of the books written every year all over the world are translated into English.
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The examples of the half-squatting, half-kneeling archers in Pit No. 2 are used to illustrate what kind of suits people wore at that time.
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Why are parenting concepts deeply rooted in the majority of families in that country?
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Why did Michael use almost every question that he had thought of and a few that he hadn’tthought of in the interview with Robert Mitchum?
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According to the poll mentioned, why are almost half of the people quite afraid of DIY?
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Birds are literally half-asleep--with one brain hemisphere alert and the other sleeping, according to a new study of sleeping ducks.
Earlier Studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere's eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the-row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing (打盹) at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through the positions in a four-duck row, the researchers found outer birds half-asleep during 32 percent of dozing time versus about 12 percent for birds in internal spots.
"We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain," the researchers say.
The results provide the best evidence for a long-standing supposition that single- hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the. lockout side could be widespread, he predicts. He's seen it in a pair of birds' dozing side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open.
Useful as half-sleeping might be, it's only been found in birds and such water mammals (哺乳动物) as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning.
Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds' half-brain sleep "is just the tip of the iceberg (冰山) ". He speculates that more examples may turn up when we take a closer look at other species.
A new study on birds' sleep has revealed that ______
A．half-brain sleep is found in all kinds of birds
B．half-brain sleep is characterized by accelerated brain waves
C．birds can control their half-brain sleep consciously
D．birds always sleep with the whole of their brain at rest
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听力原文：W：I have been waiting here for almost half an hour．Why did you take so long to park the car？
M：I'm sorry，dear．I had driven three blocks before I spotted a place to park．
Q：What do we learn from the conversation？
(14)
A．The man couldn't find a parking lot for his car.
B．The man apologized because of his carelessness.
C．The woman was upset due to his late arrival.
D．It's very hard to find a place to park the car.
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Why are the eight coins of euro different in composition, weight, thickness, and milling？
A．Because each nation wants to keep its characteristics.
B．Because they are designed by different artists from 8 countries.
C．Because it will enable the blind to distinguish between them easily.
D．Because Denmark and other countries want to have their own coins.
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which of the following is said to be the main reason why more people are looking for work？
[A] Young people start working younger.
[B] Recent graduates have entered the labor market.
[C] More people must have tow jobs to support their families.
[D] More women have entered the job market.
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They may not be the richest, but Africans remain the world's staunchest optimists. An annual survey by Gallup International, a research outfit, shows that, when asked whether this year will be better than last, Africa once again comes out on top. Out of 52,000 people interviewed all over the world, under half believe that things are looking up. But in Africa the proportion is close to 60% almost twice as much as in Europe.
Africans have some reasons to be cheerful. The continent's economy has been doing fairly well with South Africa, the economic powerhouse, growing steadily over the past few years. Some of Africa's long-running conflicts, such as the war between the north and south in Sudan and the civil war in Congo, have ended. Africa even has its first elected female head of state, in Liberia.
Yet there is no shortage of downers too. Most of Africa remains dirt poor. Crises in places like Cote d'Ivoire, Sierra Leone and Zimbabwe are far from solved. And the democratic credentials of Ethiopia and Uganda, once the darlings of western donors, have taken a bad knock. AIDS killed over gm Africans in 2005, and will kill more this year.
So is it all just a case of irrational exuberance？ Meril James of Gallup argues that there is, in fact, usually very little relation between the survey's optimism rankings and reality. Africans, this year led by Nigerians, are consistently the most upbeat, whether their lot gets better or not. On the other hand, Greece—hardly the worst place on earth—tops the gloom and doom chart, followed closely by Portugal and France.
Ms James speculates that religion may have a lot to do with it. Nine out of ten Africans are religious, the highest proportion in the world. But cynics argue that most Africans believe that 2006 will be golden because things have been so bad that it is hard to imagine how they could possibly get worse. This may help explain why places that have suffered recent misfortunes, such as Kosovo and Afghanistan, rank among the top five optimists. Moussaka for thought for those depressed Greeks.
The statistics are employed in the first paragraph so as to indicate sort of ______.
A．disparity
B．numbness
C．conformity
D．stagnation
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Why should companies do business in the language of the countries they are operating in？
A．to prevent other companies taking their business
B．to help them find new international partners
C．to meet clients' current expectations
D．to become more aware of their competitors' activities
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听力原文： An international children's charity says more than one-fourth of the children in Asia are living in absolute poverty and almost half of them are seriously deprived. In a report issued in Thailand, the group says that many Asian families are not benefiting from the region's booming economy and it has pledged $1 billion in aid over the next decade.
The charity group Plan International says 600 million Asian children are deprived of one of the seven basic needs used to define poverty, including food, safe water, shelter, health and education. And it says 350 million children, equivalent to the population of the European Union, are deprived of two or more basic needs, classifying them as absolutely poor.
The group's executive director, Tom Miller, compares these figures to those of the victims from the earthquake and tsunami that devastated parts of southern Asia eight months ago. "Those numbers are absolutely staggering. The world has focused very much on Asia through the tsunami. But in many ways, what we're talking about is, this is a silent tsunami that is happening every single day."
The group, basing its figures on United Nations statistics, says some Asian countries, like China and parts of Southeast Asia, have considerably reduced their numbers of poor children. But it says significant populations of poor people remain in isolated rural areas and among ethnic minorities.
According to the news, which of the following is not among the basic needs used to define poverty？
A．food
B．health
C．education
D．freedom
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American high school students sink almost to the bottom in a survey of math and science literacy because too many of the high school ______ in America are not qualified.
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Why crime has risen so much further and faster in Britain than in any other rich country over the past half-century is anybody's guess, maybe it's the result of near-American levels of relative poverty and family breakdown combined with a European reluctance to bang up quite such a large proportion of the population as America does. Anyway, the long-term causes are of less immediate interest to the government than a short-term solution. Popular concern about crime is rising: 23% of people rated it as one of the most important issues for the government at the beginning of this year; 34% do now.
An official report concluding that the criminal justice system is failing has added to the government's problems. The Audit Commission, the government's watchdog, says that the police too often charge suspects with the wrong offences, use inaccurate computerized information and face serious inefficiencies in the forensic science (the use of scientific methods by the police) service. Court delays alone are costing taxpayers￡80m ($120m) a year. The result is that few criminals are brought to justice and even fewer convicted. Only 6% of the more than 5m offences recorded by the police last year resulted in a conviction. Hardly surprising, then, that more than half the public believes that the criminal justice system is ineffective.
The main purpose of the White Paper published last year is to address concerns that the procedures of the court are weighted too heavily against the prosecution. It includes many sensible and uncontroversial proposals. It asks for more support for witnesses, many of whom are frightened of testifying. A survey of one London court found that, of 140 witnesses called in a two-week period, only 19 actually turned up.
Making juries more representative must also make sense. Getting off jury service is too easy. In some London courts, two-thirds of those called for jury service fail to turn up. As a result, juries are often composed of housewives, the unemployed and the retired. The White Paper recommends a check on professionals' getting off service, who can excuse themselves by saying their work is too important, and proposes penalties for those who fail to comply.
Other proposed reforms will be more controversial. At present, no defendant can be tried for the same offence twice even if compelling new evidence emerges. The government's plan to scrap that law will be resisted by civil liberties campaigners, as will the proposal that previous convictions should be disclosed in open court if they are relevant to the case being heard.
Whether or not such proposals make it into law, the White Paper did not do much to address public concerns. The reason why 94% of crimes do not result in a conviction is that three-quarters of them are not cleared up, and so nobody is charged. That is the fault of the police, not the courts; and that is the part of the criminal justice system that the government needs to focus on if it is to make a difference.
[A] use insufficient computerized information.
[B] the work of the police, not that of the courts.
[C] a short-term solution rather than the long-term causes.
[D] the mistaken offences.
[E] most of those called for jury duty are absent.
[F] to address public concerns.
[G] who are afraid of appearing in court.
According to the text, the government would pay more attention to ______
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Why are researchers seriously coneel33ed with the phenomenon of colony—collapse disorder？
A．Because honeybees produce one—third 0f the foods we eat
B．Because honeybees feed on flowers．
C．Because honeybees eat seeds of flowers．
D．Both B and C．
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请阅读短文，完成此题。Results showed that at least a tenth of the Harvard first-year undergraduates polled admitted tohaving cheated on an exam prior to starting at the university, while almost half admitted to
A、Most American students cheat in exams before they enter universities.
B、Most American students entering the universities admit they have cheated.
C、Half of students entering the universities admit to cheating on their homework.
D、There is academic dishonesty among students entering the US University.
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Why are coral reefs called the rainforests of the sea（）
A．Because they are home to a wide variety of sea life
B．Because they can protect our coasts from storms
C．Because they might supply natural medicines
D．Because they look like rainforests
